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Staircase Calculator

Design your straight staircase in seconds. Enter the total height to climb and the available floor length to get the number of steps, step height, tread depth, and Blondel formula verification.

Height from the bottom floor to the top floor (floor to floor)
Floor length available for the staircase (run)

Staircase dimensions

Number of steps

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Step height

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Tread depth

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Staircase angle

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Blondel formula (2h + g)

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How to design a staircase?

  • Blondel's rule – The formula 2h + g (2 × step height + tread depth) should be between 59 and 65 cm for a comfortable staircase. The ideal value is 63 cm.
  • Step height – The ideal step height is between 16 and 21 cm. Higher makes the staircase tiring; lower makes it too long.
  • Tread depth – The tread depth should allow comfortable foot placement, ideally between 21 and 32 cm.
  • Angle – A comfortable straight staircase has an angle between 25° and 35°. Above 45°, it becomes a ship's ladder.

Disclaimer

This calculation is a sizing aid for a simple straight staircase. Winding, spiral, or landing staircases require additional calculations. Consult a professional for any construction project.